Grand Canyon
Grand Canyon is the 12th level/chapter in the Red Faction single player campaign. It consists of two individual maps and begins with Parker exiting Capek's Inner Sanctum into the large, Grand Canyon. Grand Canyon is followed by L13 Ultor Communications Tower.
L12S1: Grand Canyon
Lower Section
L12S1 opens with Parker traversing a cavernous corridor that opens up into the expansive "Grand Canyon". Hendrix will contact you to let you know there's a disk containing a distress message that Eos was intending to bring to Ultor's Communication Center. To the right from the corridor's end is a dead end and to the left you'll find a miner parked in a Jeep who gives you the disk Hendrix told you about. The miner will ask you to jump in the back and man the turret. This is the intended path but you can continue on foot if you prefer. The following description will assume the intended path.
The miner will drive you through the Canyon as you encounter Guards, enemy Aesirs, and have your first sighting of Mercenaries brandishing Precision Rifles. On lower difficulties, you shouldn't have trouble getting through this gauntlet but on higher difficulties survival may depend on skillful shooting. At the end of the canyon, the driver will exit the Jeep and stand to the side. Some players have trouble finding where to progress from here. From where the driver stopped the Jeep, there will be some boulders on the side of the Canyon with a tunnel behind them that you'll need to crawl through to load into L12S2. You'll want to look at the L12S2 section next but at the end of L12S2 you will load back into the the "Upper Section" of L12S1.
Upper Section
After L12S2, you'll load back into L12S1 in it's "Upper Section". This is the same map as where you rode the Jeep through the canyon, even if it seems like you've gone quite a distance from that area. You'll still be in the cavern corridor but continuing through it you'll arrive at a Gondola lift station that spans across the rim of the Grand Canyon. Enter the Gondola and press the button to start the short ride across the Canyon. There are some guards you'll encounter on the other side outside of a large caverous corridor. Continue through this corridor to reach an airlock chamber. Pressing the door button on the exit will load you into L13S1.
L12S2: Dry Waterfall
L12S2 opens as Parker is still traversing the small tunnel from the end of L12S1. This tunnel ends and opens into a large cavern with a natural bridge above to the right and a body of water below to the right. The way forward is through the water. There's one small reaper patrolling the area leading down to the water. As you drop down into the water, you'll see a water-filled tunnel exiting the pool. This short tunnel will turn upward so you'll soon be out of water and faced with several more small reapers. Continue through the dry part of the tunnel and you'll come out on a ledge in the large cavern from the start of this stage. This ledge will lead to the natural bridge you saw at the beginning of the stage. The natural bridge will lead to another tunnel you'll need to traverse. At this point Hendrix will contact you to tell you no one has heard from Eos yet. He also tells you once you deliver the message on the disk, you'll need to get up to the Space Station to clear the way for the E.D.F. fleet to arrive safely.
At the end of this tunnel you'll come out onto a ledge with no land leading to a ledge on the other side. You'll have to jump to the ledge on the other side which will have another small reaper, a health pick up, an armor pick up, and some remote charges. Hendrix will contact you again and let you know about a new group of enemies you saw while riding the Jeep through the canyon: The Mercenaries led by Colonel Masako.
This is another point in the Grand Canyon level where some players have difficulty seeing where to progress. The wall rising from one end of the ledge has a vent with a grate cover. You can either walk up to this vent and press "Use" to open the cover or use the remote charges you just got to blow a hole into the vent. Climb in the vent and continue through some nasty liquid until you reach a dome where you'll hear some workers discussing their work and you'll find you just crawled through a sewer pipe. The circular domed area has a ladder you'll need to climb to get onto the top then drop down into a cavern corridor away from these workers. As you walk through this corridor, you'll load back into L11S1's Upper Section.